Liquid lens

Abstract

A liquid lens in which are contained an insulating first liquid and a conductive second liquid having non-miscibility and different refractive indexes, optical characteristics being changed by a change of an interface shape of the first and second liquids by applying a voltage to an electrode, the lens including: in a surface in contact with an edge of an interface of the first and second liquids, a first region having an affinity for the first liquid; a second region having an affinity different from that of the first liquid; and a voltage applying unit, wherein when the interface shape is changed, by an affinity force to hold the first liquid within the first region and a force to move the edge to the second region by electro-wetting, the edge can be stably held at an edge of the first region.

1. A liquid lens in which, in a container that contains a liquid, an insulating first liquid and a conductive second liquid having non-miscibility and different refractive indexes to each other are contained, wherein optical characteristics are changed by a change of an interface shape of the first liquid and the second liquid caused by application of a voltage to an electrode provided in the container, the liquid lens comprising:
 in a surface in contact with an edge of an interface of the first liquid and the second liquid, a first region having an affinity for the first liquid; 
 a second region having an affinity different from the affinity for the first liquids; and 
 a voltage applying unit, 
 wherein a plurality of the first regions and a plurality of the second regions are formed in a concentric pattern with the center of the pattern as a position of an optical axis of the lens, and 
 wherein the voltage applying unit applies the voltage such that the edge of the interface of the first liquid and the second liquid is located at one of borders of the first regions and the second regions. 
 
     
     
       2. The liquid lens according to  claim 1 , wherein the surface in contact with the edge is formed of a thin film formed on an insulating layer. 
     
     
       3. The liquid lens according to  claim 2 , wherein the insulating layer is formed perpendicularly to an optical axis direction of a light incident from outside. 
     
     
       4. The liquid lens according to  claim 2 , wherein the insulating layer is formed on an inner wall side of the container in parallel with the optical axis direction of a light incident from outside. 
     
     
       5. The liquid lens according to  claim 1 , wherein an affinity for the first liquid of the first region is higher than an affinity for the first liquid of the second region, and the affinity for the first liquid of the first region is higher than an affinity for the second liquid. 
     
     
       6. The liquid lens according to  claim 1 , wherein an affinity for the second liquid of the second region is higher than an affinity for the second liquid of the first region, and the affinity for the second liquid of the second region is higher than the affinity for the first liquid. 
     
     
       7. The liquid lens according to  claim 2 , wherein the container is formed of a cylindrical container, and the first region and the second region are formed in a circular pattern around an optical axis of the liquid lens which passes through a center of a cross section of the cylindrical container.